1. Technical Field
The present invention relates to display technology using electrophoresis of charged particles in a solution.
2. Related Art
When electrical fields are applied to a dispersion liquid in which charged particles are dispersed in a solution (dispersion medium), the particles move (electrophoretically migrate) in the dispersion medium by a Coulomb force. This phenomenon is called electrophoresis, and electrophoretic display devices (EPDs) that display desired information including images using the electrophoresis are known.
As an example structure of EPD, for example, Japanese laid-open patent application 2004-4773 (Patent Document 1) describes a structure in which a space between a pair of substrates is divided by partitions into a plurality of closed spaces (cells), and a dispersion system containing charged particles (electrophoretic particles) and dispersing medium are sealed in each of the cells.
Each of the cells of the EPD can be made to correspond to each one of pixels, and a full color display can be achieved by arranging three different colors (for example, red, green and blue) to correspond to each three of the cells. The cells may be arranged to have a structure, for example, in which (1) white particles, black particles and colored dispersion liquid are filled; (2) white particles, black particles and colored particles are filled; or (3) white particles and black particles are filled, and color filters are added.
According to the cell structures (1) and (2) described above, when a red color is to be displayed, the other two (i.e., green and blue) pixels other than the pixel displaying red are respectively controlled to be in a white or black displaying state. Specifically, in this case, the three pixels may be placed in a displaying state of (red, white and white), (red, white and black) or (red, black and black). When displaying a green color or a blue color, the remaining two pixels other than the pixel of a target color (single color) to be displayed are similarly arranged to be in a white or black displaying state.
In other words, even when one of the three primary colors (red, green and blue) is to be displayed, the target color is not displayed with the entire color area (of three pixels) of the three colors. The target color can actually be displayed with merely one third (⅓) of the color area of the three colors (three pixels), in other words, with merely one pixel.